A flange face of a wheel involves in cooperation during mounting, and the flange face must be concave but not convex according to the process requirement. In actual production, the common detection method, which is spot check with an artificial knife straight edge or with three coordinates, cannot satisfy 100% detection in automatic continuous production. Based on the current situation, the present patent provides a device for quickly detecting whether a flange face of a wheel is concave, which can be used for 100% detection in automatic production.